Mesogenic polycyanates and thermosets thereof

A polycyanate or polycyanamide composition containing one or more rodlike mesogenic moieties represented by the following Formulas I, II, III or IV ##STR34## wherein at least about 80 percent of the --A-- linkages, the direct bond in Formula III and the Y groups are in the para position with respect to each other;

• each Y is independently a --O--C.tbd.N or a --NR.sup.1 --C.tbd.N group;
• each A in Formula II when p is 1 is independently --CR.sup.1 .dbd.CR.sup.1 --, --C.tbd.C--, --N.dbd.N--,--CR.sup.1 .dbd.N--, --NR.sup.1 --CO--, --CR.sup.1 .dbd.N--N.dbd.CR.sup.1 --, --CR.sup.1 .dbd.CR.sup.1 --CO--, --CO--NR.sup.1 --, --CO--CR.sup.1 .dbd.CR.sup.1 --, --CR.sup.1 .dbd.CR.sup.1 --O--CO--(CH.sub.2).sub.n' --, --N.dbd.CR.sup.1 --, --(CH.sub.2).sub.n '--CO--O--CR.sup.1 .dbd.CR.sup.1 --, --CR.sup.1 .dbd.CR.sup.1 --O--CO--, --CO--O--CR.sup.1 .dbd.CR.sup.1 --, --CO--O--N.dbd.CR.sup.1 --, --CR.sup.1 .dbd.N--O-- CO--, --CR.sup.1 .dbd.CR.sup.1 --CO--O--, --CO--S--, --O--CO--CR.sup.1 .dbd.CR.sup.1, --CR.sup.1 .dbd.CR.sup.1 --CO--O--(CH.sub.2).sub.n '--, --S--CO--, --(CH.sub.2).sub.n '--O--CO--CR.sup.1 .dbd.CR.sup.1 --, --CHR.sup.1 --CHR.sup.1 --CO--O--, --O--CO--CHR.sup.1 --CHR.sup.1 --, --C.tbd.C--C.tbd.C--, --CR.sup.1 .dbd.CR.sup.1 --CR.sup.1 .dbd.CR.sup.1 --, --CO--NR.sup.1 --NR.sup.1 --CO--, ##STR35## and in Formulas I, IV and in Formula II when p is other than 1 or when p is 1 and Y is --NR.sup.1 --C.tbd.N, each A is independently selected from the same group as above plus --O--CO-- and --CO--O--;
• A' is a divalent hydrocarbyl group having from 1 to about 10 carbon atoms;
• each A" is independently an alkylene group having from 1 to about 10 carbon atoms, a direct bond, --O--, --CO--, --S--, --S--S--, --SO--, --SO.sub.2 -- or --O--CO--O--;
• each A.sup.1 is independently a --CO--, --O--CO--, --CO--O--, --CO--NR.sup.1 --, or --NR.sup.1 --CO-- group;
• each R is independently hydrogen or a hydrocarbyl or hydrocarbyloxy group having from 1 to about 10 carbon atoms, a halogen atom, a nitro group, a nitrile group, a phenyl group or a --CO--R.sup.1 group;
• each R.sup.1 is independently hydrogen or a hydrocarbyl group having 1 to about 3 carbon atoms;
• v has a value of one to two;
• n has a value of zero or one;
• n' has a value from 1 to about 6;
• p has a value from 1 to about 30;
• and wherein the aromatic rings can also contain one or more heteroatoms selected from N, O, or S;
• with the proviso that said polycyanate or polycyanamide composition cannot be 4,4'-dicyanatostilbene, 4,4'-dicyanamidoazobenzene, 4,4'-dicyanamidobenzanilide, 4,4'-dicyanamidophenyl benzoate, dicyanates of the diphenol esters of terephthaloyl chloride and bisphenol A, 4,4'-dihydroxydiphenyl, and dicyanates represented by the following formulas ##STR36## wherein Ar is an aromatic radical selected from the group consisting of 1,4'-benzene, 1,4-naphthalene, 1,5-naphthalene, 2,6-naphthalene, 2,7-naphthalene, 4,4'-biphenyl or 4,4'-diphenylalkylene radicals and can possess any nonactive hydrogen-containing substituent(s) which do not remove mesogenicity.